This invention relates to filters and more particularly to filters used for filtering swimming pool water.
Swimming pools require that their water be filtered in order to assure water of sufficient cleanliness for bathing. Existing swimming pools, both above and below ground, require complicated and expensive filters of sufficient size to efficiently filter pool water. Since the water from the swimming pools must be forced through these filters, pumps used for swimming pool filters require relatively large motors, commonly in the 1-hp. . . range, which consume relatively large amounts of electricity. Furthermore, most prior art swimming pool filters require backwashing periodically. Since the water used for backwashing must be drawn from the pool and then discharged, backwashing the filter consumes a significant quantity of water which must be replaced. Many swimming pools are used in sections of the country which impose water restrictions on residents and/or which normally experience drought conditions in which the water required for backwashing is a significant consumption of water. Furthermore, existing swimming pool filtering systems require complicated plumbing, in which pipes run between the skimmer, and the main drain, the pump, the filter, and the pool inlets, and further require a strainer separate from the filter at the pump inlet.
According to the present invention, a filter housing mounted adjacent to the pool is provided a skimmer inlet and/or an inlet connected to the main drain of the pool, both of which receive pool water for filtering. A removable perforated basket is mounted within the housing between the inlet from the skimmer and the inlet from the main drain so that the water passing through the skimmer also passes through the strainer. Water is then communicated through a filter bag which is supported away from the walls of the housing by a perforated liner. The basket and filter bag are accessible from an opening above the water level of the pool, so the filter may be serviced without shutting off valves, etc. After passing through the filter bag, the water passes to an outlet chamber which is communicated through the inlet of a pump to an outlet port of the housing. In the case of the aboveground pools, in which the entire assembly is mounted above ground level, a pump may be mounted directly on the filter housing and connected directly to the outlet port. The size of the pump may be relatively small, such as about {fraction (1/15)} hp. The small pump is satisfactory because the filter bag is at the inlet of the pump. Adjustable legs are provided on the filter housing to provide a support for the filter. Instead of backwashing, the filter bag is changed and discarded periodically. A strainer at the pump inlet separate from the filter is eliminated. In below ground pools, the filter housing is below ground, and the pump is mounted away from the housing and only a single inlet line and a single return line need to be connected to the pump, thereby simplifying plumbing.